Furnace



H. G. WElDENTHAL, DECD.

L. s. WEIDENTHAL, ADMINISTRATRIX FURNACE. v

APPLICATION FILED JULY 29.1920.

/ 1,410,086, Patented Mm:21,1922.

llllll llllll PATENT OFFICE.

HARQLID G. WEIDENTHAL, 0F CLEVELAND, OHIO; LOUISE S. WEIDENTHAL ADMINIS- TRATBIX 0F SAID HAROLD G. WEIDENTHAL, DECEASED.

FURNACE.

" Application filed. July 29,

T 0 all whom it may concern:

Be it known that I, HAROLD Gr. l/VEIDEN- THAL, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Furnaces, of ,which the following is a full, clear, and exact description, referencebeing had to the accompanying drawings.

This invention relates to metallurgical furnaces and especially to electric furnaces although not by any means limited thereto. The objects of the. invention are the provision of a roof and lining so constructed-as to possess greater mechanical strength and longer life than heretofore; the provision of a new and improved mode of securing in place a lining of a furnace; the provision of a furnace lining and roof which shall better withstand the high temperatures to which they are subjected; the provision of an improved brick or block for furnace linings; while further objects and advantages will appear as the description proceeds. I

The temperaturesemployed in many metallurgical operations of the present.day are higher than the melting point of the material of which the furnace itself is made,

as a consequence of, which the furnace lining is rapidly melted or eroded away until it reaches such a thickness that the heat loss from the exterior brings the interior surface down to a temperature that the furnace material will survive. This thickness varies with the heat conductivity of the different substances used for linings and also with the furnace construction which may affect the rate of heat loss from the exterior surfaces. IVith brick of the type ordinarily .used for the roof of electric furnaces, equi- 11br1um 1s generally attained when a thickness of approximately five inches has been attained, yet the bricks are generally made with an original thickness of about nine inches for the purpose of securing greater mechanical strength. The result is that half the thickness of the brick is melted or eroded away within the first few hours of operation, after which the furnace remains constant until the occurrence of a slight blow or jar which causes the collapse of the roof due to its deficiency of mechanical strength.

Likewise the wall bricks are generally 15 to 18 inches thick when new but do not reach Specification of letters Patent.

Patented Mar. 1922.

1920. Serial No. 399,706.

equilibrium until burned back toliiltibout 9 inches.

Accordingtoniy invention, I form each brick with an external cavity open to the outerv air and extending inwardly into the brick sufliciently far so that its cooling effect is sufficient to preventany serious destruction of the inner surface. In. this way I secure suflicient lateral-surface of each brick to afford the necessary mechanical strength while also securingsufiicient radiation to maintain the inner face of the brick at a sufliciently low temperature to prevent serious disintegration. I also utilize this con struction as part of an expedient to' secure .the lining bricks in place upon the furnace wall by forming such wall with metal studs -which enter the cavities in the bricks and .and working openings where it is difficult to support the liningbrioks, and at the upper rearward wall of tilting furnaces, and in places where bricks are frequently renewed. It is a further feature of my-invention to introduce into the cavity of the brick a material of higher conductivity than the brick substance, tending to maintain lining. As a practical economical to suffer a slightly increased heat loss and thereby maintain the furnace in condition alonger period of time than to save a few per cent in current used at the cost of frequent repairs and long shutdowns. v y

In the drawings accompanying and forming a part of this application, I have shown the preferred embodiment of my invention although it will be understood that the illustrations herein are merely suggestive of types and not exhaustive of structure' In thesedrawings, Fig. 1 represents a top plan view of one design of a top for electric furnaces; Fig. 2 is a vertical sectional view through the top and side walls of the furnace; Fig. 3' is a sectional view of the furthe integrity of the matter it is far more thereby still further nace drawn to smallerscale and showingtional view through one of the wall bricks together with its support.

The top of such a furnace ordinarily comprises a circular metal hoop 1 having built immediately within it a ring 2 of fire brick or other refractory material which in turn supports the arched roof formed of bricks of various shapes and sizes. Different manufrcturcrs employ different designs, and the particular design shown is not important to my invention. However, I form each brick which is subjected to the furnace heat with one or more outwardly opening cavities 5 of such depth as to cool the'interior faceof the brick to the necessary degree and also to afford a sufficiently wide lateral face to secure the desired mechanical strength.

The side wall of the furnace is generally made of a metal shell 10 lined interiorly with bricks 11, the lower portions being lined in turn with a refractory hearth material 12, generally molded in place. The sides of the shell are formed with a pouring opening 13 and one or more working openings l t, while the top is closed by means of the cover previously described which rests more'or less tightly thereon. According to my invention, I form each of the wall bricks above the hearth with an outwardly opening cavity 15, and I preferably provide the shell with inwardly projecting metal studs 16 upon 'which these bricks are lodged. These studs are also preferably hollow, for the double purpose of permitting the access of air to the brick interior and also of enabling the insertion of a rod with which to knock the brick from its seat if and when it is desired to replace the same. These studs, whether hollow or solid, act by reason of the increased conductivity to cool the brick material and hence to reduce the temperature of its inner face, and also permit the movement of air to cool the bricks. They are preferably held in place by spin- 'ning or riveting the metal thereof into contact with the metal shell, although the same can be bolted in place if desired. The studs are generally located in a slanting position with their inner ends uppermost, and themdividual bricks formed with their upper and lower faces parallel to the cavity and oblique to their end faces, thus causing a kind of interlocking which greatly impedes their accidental dislocation This construction not only renders the furnace lining longer lived but facilitates the replacement of individual bricks since the various. units are not so dependent upon each other for their support as heretofore. This is a particularly important feature at the top of the furnace and near openings because of the ac cidental damage to the lining due to mechanical shocks and to the erosive action of the escaping flame and gases.

It will be understood that I do not restrict myself to a construction in which the furnace has a complete external shell, since the same can be made as a skeleton or even omitted; and likewise many other modifications can b made within the scope of my invention; wherefore I do not limit myself in any manner except as specifically recited in the claims hereto annexed.

Ilaving thus described my invention, what I claim is 1. A brickpr lining unit for metallurgical furnaces made of refractory material and having an outwardly opening cavity of uniform here throughout and extending sufficiently near the inner face thereof to assist in cooling the same.

'2. A brick or lining unit for metallurgical furnaces consisting of a hollow flat sided block of refractory material having an opening only in that face which is turned outwardly, the bore of said cavity being uniform from end.t0 end.

3. A brick or lining unit for metallurgical furnaces made of refractory material and having an outwardly opening cavity extending to a point sufficiently near the inner face thereof to assist in cooling the same, and a hollow heat conducting body located in said cavity, said body being open at both ends.

4. In a device of the character described, a lining built up of blocks of refractory material and being the thickness of a single block, certain blocks having cavities opening through their outer faces and extending sufficiently near the inner faces of the same to assist in cooling them, the cavities being of uniform bore throughout.

5. In a'furnace, a metal shell, a lining therein consisting of blocks of refractory material, certain of which have cavities in their outer faces, and metal studs attached to said shell and projecting into said cavities, so as to hold the blocks in place and also to conduct heat away from their inner faces.

6. In afurnace,a metal shell, a lining therein consisting of blocks of refractory material, formed with cavities in their outer faces, and heat conducting bodies in said cavities, said bodies making thermal contact with said shell.

7. In a furnace, a metal shell, a lining therein consisting of blocks of refractory material, certain of said blocks having in their outer faces a cavity which extends sufficiently near the inner face to assist in cooling the same, in combination with hollow metal studs carried by said shell and projecting into said cavities.

8. In a furnace, in combination, a metal shell having a plurality of inwardly projecting oblique metal studs, and lining blocks of refractory material having cavities loosely receiving said studs.

9. In a furnace, in combination, a metal shell having a plurality of inwardly projecting hollow oblique metal studs, and lin ing blocks of refractory material having cavities loosely receiving said studs.

10. In a furnace, in combination, a metal I shell having a plurality of inwardly pro- 11. In a furnace, in combination, a metal shellhaving a plurality of inwardly project ing oblique metal studs, and lining blocks of re ractory' material having cavities loosely receiving said studs, the sides of said blocks being parallel to said studs and the inner "faces of said blocks being parallel to, the

shell at that point. 4

12.- In a furnace, in combination, ametal shell having a plurality of inwardly projecting, hollow, oblique, metal studs, and lining blocks having cavities loosely receiving said studs, the sides of'said blocks which contact with the other blocks beingparallel signature.

HAROLD e. wEiDENTHAL. I

to said studs and the inner face of said blocks being parallel to the metal shell at that point.

13. A lining block for furnaceswnade of refractorymaterial and having the shape of an oblique parallelepipedon, there being; a

cylindrical cavity opening through onefacc;

of the same.

made in the shape of an oblique parallelepipedon and havinga cylindrical cavity opening through a single face thereof, the

axisof said cavity being parallel to the'side 14. A refractory lining block for furnaces faces of the block and oblique ,to that face through which itopens.

15. A roof for furnaces made of blocks of refactory material whose outer faces are formed with cavities which extend inwardly a d'acent their inner surfaces.

n testimony whereof, I hereunto affix 

